The invention relates to a turbine ring assembly comprising a plurality of ring sectors made of ceramic matrix composite material, together with a ring support structure.
When turbine ring assemblies are made entirely out of metal, it is necessary to cool all of the elements of the assembly, and in particular the turbine ring that is subjected to the hottest stream. Such cooling has a significant impact on the performance of the engine since the cooling stream used is taken from the main stream through the engine. In addition, using metal for the turbine ring limits potential for increasing temperature in the turbine, even though that would enable the performance of aeroengines to be improved.
In an attempt to solve such problems, proposals have been made to have recourse to turbine ring sectors that are made of ceramic matrix composite (CMC) material in order to avoid making use of a metal material.
CMC materials present good mechanical properties making them suitable for constituting structural elements, and advantageously they conserve these properties at high temperatures. Using CMC materials has advantageously made it possible to reduce the cooling stream that needs to be used in operation, and thus to improve the performance of engines. In addition, using CMC materials advantageously makes it possible to reduce the weight of engines and to reduce the effect of expansion when hot as encountered with metal parts.
Nevertheless, existing proposed solutions may involve assembling a CMC ring sector by using metal attachment portions of a ring support structure, these attachment portions being subjected to the hot stream. Consequently, the metal attachment portions are subjected to expansion when hot, and that can lead to the CMC ring sector being subjected to mechanical stress and being weakened.
Also known are Documents GB 2 480 766, EP 1 350 927, and US 2014/0271145, which disclose turbine ring assemblies.
There exists a need to improve existing turbine ring assemblies that use CMC material in order to reduce the magnitude of the mechanical stresses to which the CMC ring sectors are subjected in operation.